C# - Download Email in Background

In an ASP/ASP.NET email application, if email download takes longer than the timeout value (in seconds) that the current asp page is allowed to run, user will get an error “ASP Timeout”. This often happens when user has a large quantity of emails to download or user downloads emails via a slow connection. By default the timeout is set to 90 seconds, it is easy to exceed this limit.

Obviously, a solution to ASP timeout is to set ASPScriptTimeout a larger value. You may click here for details. Technically the timeout problem can be solved in this way; however, some users may get frustrated and press the stop button on the browser toolbar as he waits too long.

EAGetMail POP3 Component introduces a more intelligent method to retrieve emails in background. You should download the EAGetMail Service installer and install it on your machine at first. Then you can use MailClient.GetMailsByQueue method to send the request to EAGetMail Service, the method returns to the user immediately and the EAGetMail Service performs task in background.

Important

To run the following example, you need to download EAGetMail and EAGetMail Service at first, and then install both on your machine.

The following c# example codes demonstrate how to download email from POP3 server in background.

Installation

Before you can use the following sample codes, you should download the EAGetMail Installer and install it on your machine at first. Full sample projects are included in this installer.

Install from NuGet

You can also install the run-time assembly by NuGet. Run the following command in the NuGet Package Manager Console:

Install-Package EAGetMail

Note

If you install it by NuGet, no sample projects are installed, only .NET assembly is installed.

Add Reference

To use EAGetMail POP3 & IMAP Component in your project, the first step is “Add reference of EAGetMail to your project”. Please create or open your project with Visual Studio, then go to menu -> Project -> Add Reference -> .NET -> Browse..., and select EAGetMail{version}.dll from installation path, click Open-> OK, the reference will be added to the project, you can start to use it to retrieve email and parse email in your project.

add reference in c#/vb.net/managed c++/cli

.NET Assembly

Because EAGetMail has separate builds for .Net Framework, please refer to the following table and choose the correct dll.

Separate builds of run-time assembly for .Net Framework 1.1, 2.0, 3.5, 4.0, 4.5 and .Net Compact Framework 2.0, 3.5.

File .NET Framework Version
EAGetMail.dll Built with .NET Framework 1.1
It requires .NET Framework 1.1, 2.0, 3.5 or later version.
EAGetMail20.dll Built with .NET Framework 2.0
It requires .NET Framework 2.0, 3.5 or later version.
EAGetMail35.dll Built with .NET Framework 3.5
It requires .NET Framework 3.5 or later version.
EAGetMail40.dll Built with .NET Framework 4.0
It requires .NET Framework 4.0 or later version.
EAGetMail45.dll Built with .NET Framework 4.5
It requires .NET Framework 4.5 or later version.
EAGetMailCF20.dll Built with .NET Compact Framework 2.0
It requires .NET Compact Framework 2.0, 3.5 or later version.
EAGetMailCF35.dll Built with .NET Compact Framework 3.5
It requires .NET Compact Framework 3.5 or later version.

C# - Download Email in Background - Example

The following example codes demonstrate downloading email from POP3 server in background. In order to run it correctly, please change email server, user, password, folder, file name value to yours.

Note

To get full sample projects, please download and install EAGetMail on your machine.

using System;
using System.Collections.Generic;
using System.Text;
using System.IO;

// Add EAGetMail namespace
using EAGetMail;

namespace receiveemail
{
    class Program
    {
        static void Main(string[] args)
        {
            // Create a folder named "inbox" under current directory
            // to save the email retrieved.
            string curpath = Directory.GetCurrentDirectory();
            string mailbox = String.Format("{0}\\inbox", curpath);

            // If the folder is not existed, create it.
            if (!Directory.Exists(mailbox))
            {
                Directory.CreateDirectory(mailbox);
            }

            MailServer oServer = new MailServer("pop3.emailarchitect.net",
                        "test@emailarchitect.net", "testpassword", ServerProtocol.Pop3);
            MailClient oClient = new MailClient("TryIt");

            // If your POP3 server requires SSL connection,
            // Please add the following codes:
            // oServer.SSLConnection = true;
            // oServer.Port = 995;

            try
            {
                // Leave a copy of message on server.
                bool leaveCopy = true;

                // Download emails to this local folder
                string downloadFolder = mailbox;

                // Send request to EAGetMail Service, then EAGetMail Service retrieves email
                // in background and this method returns immediately.
                oClient.GetMailsByQueue(oServer, downloadFolder, leaveCopy);
            }
            catch (Exception ep)
            {
                Console.WriteLine(ep.Message);
            }

        }
    }
}

Appendix

Comments

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